The present invention relates to a new type of city refuse incinerator with which the formation of clinkers inside a furnace body is easily and thoroughly prevented.
Due to remarkable recent improvements in living standards and the extensive use of plastics, refuse from households, plants, etc. (hereinafter called city refuse), contains a large amount of waste plastic materials, thus making the calrolific value of refuse especially high.
However, when refuse with such a high calorific value is given a combustion treatment, clinkers such as melted ash, etc., are formed on sidewalls of a furnace body due to an elevated temperature inside the furnace, thus making continuous operation of an incinerator difficult.
To avoid such a problem relating to clinkers as stated above, a means of preventing the formation of clinkers has been employed in which excessive temperature rises of the sidewalls of a furnace are suppressed by means of employing a wall structure with water-wall tubes at the sidewall area of the furnace body (so-called clinker zone) where clinkers tend to be easily formed. Also, a means of preventing the formation of clinkers by reducing the temperature of sidewalls of a furnace using a water gas reaction caused by steam sprayed along the surface of sidewalls of the furnace from both sides of stoker type firing equipment has been conventionally employed.
It is relatively easy to employ such methods to prevent the formation of clinkers as stated above with a city refuse incinerator equipped with a waste heat boiler.
However, in the case of a small or medium size city refuse incinerator which is not equipped with a waste heat boiler, it is not easy to employ such methods to prevent the formation of clinkers as stated above due to high installation costs.
That is, an extra steam generation device is required when steam is sprayed onto the sidewalls of a furnace, while a cooling water circulation device or a water cooling device are required in the case of changing an ordinary furnace wall to a water-wall.
Due to these extra requirements, small and medium size refuse incinerators not equipped with a waste heat boiler are not usually provided with a clinker formation preventing device, thus causing various kinds of problems that cause difficulties in operating these incinerators due to the formation of clinkers.